Troubleshooting Common Arma Reforger Server Issues

Introduction

Even a well-configured Arma Reforger server runs into trouble eventually – crashes, connection failures, mod mismatches, performance drops. This one is on heavy rotation on our ticket queue, so here's what we check first when a Reforger box is misbehaving.

If you haven't set the server up yet, start with our Getting Started Guide. For the full config reference, see the Server Configuration Guide.

Server Won't Start

Symptoms

The server process exits immediately after launching, or the console shows errors during startup.

Common Causes and Fixes

Invalid JSON in config file

The most frequent cause of startup failures is a syntax error in your config.json. JSON is strict – a missing comma, a trailing comma, or a mismatched bracket will stop the server loading.

• Run your config through a JSON validator like jsonlint.com.
• Check for trailing commas after the last item in arrays or objects – JSON does not allow them.
• Make sure all strings use double quotes, not single quotes.

Invalid scenario ID

If scenarioId doesn't match a valid mission, the server will fail to load.

• Double-check the scenario ID against the list in our Configuration Guide.
• If you're using a scenario from a mod, make sure the mod is listed in your mods array and the mod ID is correct.

Port conflict

Your LOW.MS server has pre-allocated ports. The bindPort in your config must match the game port shown in your control panel (typically 2302 on LOW.MS). Don't change it unless support tells you to – it has to match your allocation.

Mod loading failure

A corrupted or incompatible mod can stop the server booting.

• Clear the mods array and restart. If it comes up clean, add mods back one at a time until you find the culprit.
• Verify each mod ID against the Arma Reforger Workshop.

Players Cannot Connect

Server not visible in browser

If your server isn't showing up in the in-game browser:

1. Check visible is true in the game block of your config.
2. Confirm the server has actually finished loading – while a scenario is still loading, it won't advertise.
3. Give it a few minutes. Newly started servers don't appear instantly in the listing.
4. If you've just restarted, double-check the process is running in Current Activity & Stats in your control panel.

Version mismatch errors

This happens when the client and server are on different Reforger versions.

• Server side: after a game update, your server files need to match. LOW.MS updates the server for you in most cases. If the error sticks around, restart the server (which triggers the update) or drop us a ticket.
• Client side: make sure the connecting player has updated their game via Steam or their console store.

Connection timeout errors

Players see a timeout when joining:

1. Is the server actually running? Check Web Console or Current Activity & Stats in the panel – it might be in a crash loop.
2. Correct IP and port? Verify against the values shown in your control panel.
3. Server full? If you've hit maxPlayers, new joins time out.
4. BattlEye mismatch: if battlEye is true on the server, the client needs BattlEye enabled too. Players who disabled it can't join.

Mod mismatch errors

The server's mod list doesn't match what the client has.

• Make sure players are subscribed to every mod in your list via the Workshop.
• If you've pinned specific versions in your config, players need those exact versions.
• Share your full mod list with players so they can grab everything before connecting.

Server Crashes

Crash on startup with mods

If the server crashes during the loading phase with mods enabled:

1. Clear the mods array and restart. If it runs clean, the issue is mod-related.
2. Add mods back one at a time, restarting after each, until you find the one that breaks it.
3. Check the Workshop page of each mod for known incompatibilities.
4. Update mods – outdated ones may not match the current server build. Remove any version pins and try the latest release.

Crash during gameplay

Servers that crash mid-session usually hit one of these:

• Memory exhaustion – Watch your RAM usage in Current Activity & Stats. Heavier servers running mods and high player counts need more RAM, and if you're pinning the limit you'll want to move up to a larger RAM tier. See the options on our Arma Reforger page.
• Long uptime – Reforger servers can slowly leak memory over long sessions. Schedule automatic restarts every 6-12 hours via Scheduled Tasks.
• Specific mod issues – If crashes happen at predictable moments, suspect whichever mod you most recently added.

Crash after a game update

When Bohemia ships an Arma Reforger patch, the server needs to match:

1. Restart the server to trigger the update.
2. Check mods are compatible with the new version – modders sometimes take a few hours or days to catch up.
3. If the server keeps crashing, temporarily disable mods until their updates land.

Performance Issues

High latency and lag

Players getting high ping or rubberbanding:

1. Reduce networkViewDistance – this is the biggest single lever. Dropping it from the default 1500 to something like 1000 noticeably cuts network load.
2. Reduce serverMaxViewDistance – lower rendering distance means less server-side work.
3. Lower maxPlayers – a smooth 48-slot server beats a laggy 64-slot one.
4. Check RAM headroom – if the server is running out of memory, performance falls off a cliff. Move to a larger RAM tier if you need more.
5. Rein in AI – in Game Master scenarios, big AI counts are the number one cause of server lag. Keep the count sensible for your slot count.

Gradual performance degradation

If the server starts fine but gets worse over hours:

• Schedule restarts – honestly the most reliable fix. A fresh boot clears accumulated memory and resets the sim state.
• Watch resource usage – track CPU and RAM over time in the panel. RAM that climbs and never plateaus usually means a leaking mod.
• Reduce entity count – in Conflict, base building and abandoned vehicles pile up. Mission or server restarts clear the slate.

Scenario-specific performance

Different modes behave very differently:

Crossplay Issues

PS5 players cannot join

Since Update 1.4 (22 May 2025), PS5 does support Workshop mods on Reforger – see the Bohemia 1.4 announcement. That said, individual mods can still be flagged PC-only or PC/Xbox-only by their authors, depending on whether they ship script code (a Sony restriction) or just data assets.

If PS5 players can't join your server:

1. Check every mod's platform flag on the Workshop. If any mod in your list is marked PC-only or PC/Xbox-only, PS5 joins will be blocked. Either swap the mod for a PS5-compatible alternative or accept the platform restriction.
2. Confirm crossPlatform is true in your config.
3. Confirm supportedPlatforms includes PLATFORM_PSN.
4. Make sure BattlEye settings line up across all platforms.

Xbox players cannot join

1. Confirm supportedPlatforms includes PLATFORM_XBL.
2. Confirm crossPlatform is true.
3. Mods on Xbox work much like PS5 – players need the same mods via the in-game Workshop, and individual mods can still be platform-flagged.

Mod-Specific Issues

Mods not loading

If mods appear in your config but aren't active on the server:

• Check the mod ID – copy it directly from the Workshop page. A single wrong character breaks it.
• Check server logs in Log Viewer – the console output shows mod loading progress and errors.
• Mod availability – the mod may have been unpublished or set private by its author.

Mod conflicts

Signs of a mod conflict:

• Crashes only when certain mods are loaded together.
• Game-breaking bugs that only appear with specific combinations.
• Error messages referencing particular mod assets in the console.

The fix is a binary search: disable half your mods, test, then keep halving the problem set until you find the offender. For a walkthrough of the mod install workflow, see How to Install Mods.

Getting Further Help

If none of the above sorts it out:

1. Check the server console. The most useful diagnostic info lives in Log Viewer and Web Console. Copy any errors you see.
2. Open a ticket. If you've worked through this and it's still broken, drop us a ticket via the LOW.MS Control Panel and include your server logs – the first 50 lines after startup usually tell us what's wrong. Support is 24/7.
3. Bohemia resources. The official Arma Reforger Known Issues page tracks game-level bugs that can affect servers.
4. Community. The Arma Reforger subreddit and Discord are both active and full of experienced admins.